Self examination of the eye is useful for a number of purposes. Sufferers of diseases of the eye, for instance, may need to inspect the eye closely for indications of its condition. Also, users of contact lenses often encounter problems with debris or air bubbles between the lens and the eye, which can lead to irritation of the surface of the eye, pain, and potential permanent damage to the cornea. The kind of detailed self inspection of the eye required for these and many other purposes is presently impossible to accomplish alone.
Several diseases of the eye are indicated by the visual condition of the eye, such as glaucoma or keratoconus, for instance. People who suffer from these diseases may need to closely monitor the visual condition of the eye regularly. While it is possible of course to have one's eye condition checked by a doctor, for a variety of reasons it is not always convenient to visit a doctor at a frequency that may be required.
Also, for people who may not suffer such diseases but may simply wear contact lenses, an inspection of the eye can be most useful.
It is also most difficult, if not impossible, for an individual to self-inspect the installation on the eye of piggy back lens systems of my previous U.S. Pat. No. 5,434,630, herein incorporated by reference. In order to ensure that the two lenses of that invention are properly configured, a very close inspection of the eye surface is required that is not possible using only a mirror. The '630 invention may not be operable with air bubbles or foreign matter between lenses. Further, while it may at times be possible to see or feel that an air bubble or debris is present using a mirror or other means, it is most difficult or impossible to determine whether the bubble or debris lies between lenses or between the eye and the bottom lens. The consistent presence of such bubbles or debris over the long term can lead to permanent and painful damage to the eye.
Devices have been described which allow for the self examination of the eye. These devices, however, may not prove useful for inspecting the eye to look for air bubbles or debris under a contact lens.
U.S. Pat. No. 3,787,112, for instance, discloses a method and apparatus for ocular self examination. The device claimed and described introduces non-collimated light into the eye. A chart is then viewed, with the user seeing shadows on the chart corresponding to any damage on the retina, tumors, or scar tissue. The device of the '112 patent does not reflect an image of the eye itself, and therefor does not allow for an inspection of the actual eye surface. It instead shines light into the eye and provides a magnified chart to be read. Things such as air bubbles under a contact lens may not be detecatable with this device. For these reasons, the device of the '112 patent is of little use in detecting materials such as air bubbles under a contact lens. Further, the device and method disclosed relate to a large, bulky apparatus that does not lend itself to portability.
U.S. Pat. No. 3,903,870 also describes a method and device for ocular self examination. The '870 device utilizes a point source of light placed at the anterior focus of the eye. Because this point source is located at the anterior focus of the eye, light beams from it will be reflected and collimated from the rear surface of the eye, the retina. This will in turn cause an image of the retina to be reflected outward. The user may thereby inspect the image and compare it to images of healthy retinas to discern any differences and thus be alerted to potential problems. The '870 device is thus not particularly useful to detect such things as debris under a contact lens, or a damaged or inflamed cornea. Also, as the '870 device uses only a point light source and not a lens, the observed image may not be magnified to an extent required to observe with sufficient detail the eye, particularly for users with limited vision.
Neither the invention of the '870 patent nor that of the '112 patent, nor similar devices, would be useful for using the subject of my previous U.S. Pat. No. 5,434,630. The '870 device or the '112 device would not be able to adequately indicate the orientation of the piggy-backed lenses on the eye surface as is required to properly use the subject of my '630 patent.
An unresolved need therefor exists for an easy to use device for the self visual inspection of the condition of the eye.